docs: def _find_clim_vars(self, ds, refresh=False):
          '''
          Returns a list of variables that are likely to be climatology variables based on CF §7.4
  
          :param netCDF4.Dataset ds: An open netCDF dataset
          :param bool refresh: if refresh is set to True, the cache is
                               invalidated.
          :rtype: list
          :return: A list containing strings with geophysical variable
                   names.
          '''
  
          if self._clim_vars.get(ds, None) and refresh is False:
              return self._clim_vars[ds]
  
          climatology_variable = cfutil.get_climatology_variable(ds)
          if climatology_variable:
              self._clim_vars[ds].append(climatology_variable)
  
          return self._clim_vars[ds]